DESCRIPTION (Applicant's abstract): This project will investigate the neural basis of response selection using functional magnetic imaging (fMRI). Functional imaging is playing an increasingly significant role in cognitive neuroscience research, including the topics of memory, vision and motor control. The proposed experiments are an attempt to integrate behavioral and imaging findings in these three areas using a paradigm called the flanker task The flanker task has been shown behaviorally to evoke response selection processes for stimuli that do not elicit an overt response. A procedure is developed to isolate the neural loci of these selection processes and to examine their sensitivity to stimulus properties. With this new method, a new understanding of the interaction between selective attention and response competition can be created.